What is the purpose of the Mysterious set (mysterious book, mysterious token and the mysterious bucket)??? I figured out most of the effects these items provide, but still have NO IDEA what bonuses it gives if you have the whole set equiped; there are only some numbers!
Well, maybe is related to the mysterious teleporter stone. (some strange creature with a bag, that appears randomly, drops it before it escapes - PUF! ; it's at the end of the Bestiary - Act III).
That myserious teleporter is listed in your Quest Items part of the Journal.
I don't understand nothing else of the whole thing about those "mysterious" items.